HEIDENHAIN TNC 620 User Manual page 157

Fixed Cycles: Pocket Milling / Stud Milling / Slot Milling | CIRCULAR POCKET (Cycle 252, DIN/ISO: G252,
software option 19)
Finishing
1 Inasmuch as finishing allowances are defined, the TNC then
finishes the pocket walls, in multiple infeeds if so specified.
2 The TNC positions the tool in the tool axis in front of the
pocket wall, taking the finishing allowance Q368 and the set-up
clearance Q200 into account.
3 The TNC clears the pocket from the inside out until the diameter
Q223 is reached.
4 Then the TNC again positions the tool in the tool axis in front
of the pocket wall, taking the finishing allowance Q368 and the
set-up clearance Q200 into account, and repeats the finishing
process of the pocket wall at the next depth.
5 The TNC repeats this process until the programmed diameter is
reached.
6 After machining to the diameter Q223, the TNC retracts the
tool tangentially by the finishing allowance Q368 plus the set-
up clearance Q200 in the working plane, then retracts at rapid
traverse to the set-up clearance Q200 in the tool axis and
returns to the pocket center.
7 Next, the TNC moves the tool in the tool axis to the depth Q201
and finishes the floor of the pocket from the inside out. The
pocket floor is approached tangentially.
8 The TNC repeats this process until the depth Q201 plus Q369 is
reached.
9 Finally, the tool moves away from the pocket wall tangentially
by the set-up clearance Q200, then retracts at rapid traverse to
the set-up clearance Q200 in the tool axis and returns at rapid
traverse to the pocket center.
HEIDENHAIN | TNC 620 | User's manual for cycle programming | 10/2017
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